The Duplicate Signups

Ravensworth Books ran a newsletter signup during a sale and the form happily accepted the same person more than once — some clicked twice, some came back the next day and signed up again. The mailing service bills per subscriber, so the number the finance team needs is how many different people are on the list, not how many times the form fired.

Task: Print how many different email addresses appear in the signup log.

Input

The first line holds one integer n, how many signups follow. Each of the next n lines holds one email address. Addresses may use any mix of upper and lower case, and they are compared exactly as they were written — two addresses that differ only in case are two different addresses. Repeats may appear anywhere in the log rather than next to each other.

Output

One line holding a single whole number: how many different addresses the log contains.

Example:

Input:
4
a@x.com
b@x.com
a@x.com
c@x.com

Output:
3